Introduction to Unit 2
Psychology
Unit 2
• Research methods
• Memory
• Intelligence
• Abnormality
Research
Methods
• Research methods is a fundamental part to studying psychology and within
this topic we will explore the different research methods employed by
psychologists to carry out research. We will look at the structure of a
psychological report in preparation for students carrying out their own
research. We explore statistical analysis using this to draw conclusions within
research.
•
Memory
• This topic explores different models of memory in
explaining how we store information in the brain. In
addition to this we also look at reasons why we forget.
Abnormality
• We explore depression and schizophrenia in this
topic focusing on explanations of the disorders.
We also learn about modern day treatments for
these illnesses comparing their effectiveness in
rehabilitating people.
Intelligence
• This topic looks at theories of intelligence and
explore evolutionary psychology. We explore how
species have evolved and adapted to aid survival
and how brain size is relative to the species.
Assignment 3
• 2000 word Research Project
• Due w/c 21st April
• Investigate one model of memory and report your research findings in
a formal academic report.
Assignment 4
• 2 hr Exam
• 3rd of June
• Will be to do with Depression and Intelligence
Introduction to Experiments
• The aim of today’s lesson is to investigate the use of
laboratory experiments in psychology.
Carrying out research in psychology: Aim
• In order to carry out a study we must firstly decide upon
the aim.
• The aim is a statement of what we are intending to
research.
• For example: to investigate the effects of binge drinking
in the North East amongst different age cohorts.
Hypothesis
• Before we carry out research in psychology we write a
hypothesis.
• A hypothesis is a specific and scientific statement of what
we are intending to find.
• There are two different types of hypotheses which we
write: Alternative hypothesis and Null hypothesis
Alternative hypothesis
• This is a precise statement which always states that a
difference will be found between the groups being
studied.
• EG There will be a difference in the amount of binge
drinking in different age cohorts in the North East
Null Hypothesis
• This is a precise statement which always states no difference
will be found amongst the groups being studied.
• We also usually write at the end of a null hypothesis ‘any
differences found will be due to chance’
• EG There will be no difference in the amount of binge
drinking in different age cohorts in the North East
Directional or non-directional
• There are also two different types of alternative
hypothesis: directional and non-directional.
• A directional hypothesis will always state the precise
direction in which the results will go in.
• Hint! Directional hypotheses always have words in them
such as more, less, increase, decrease to indicate direction
Non directional
• A non directional hypothesis will state that a difference
will be found between the two groups but doesn’t state
where that difference will be.
What is an experiment ?
• An experiment is a controlled situation in which
the researcher manipulates one variable to discover
its effect on another variable, while the other
variables are held constant.
Variables
• In any experiment there must be
two “variables”
• The independent variable is what
we manipulate
• And the dependent variable is the
result/what we measure because it
depends on what we do !
Jacobs: General Theory
• “Sort Term Memory has a limited capacity”
• This is a sensible idea, but it doesn’t give us any ideas
about how we will test the hypothesis, the general shape
of the experiment
• So we need an experimental hypothesis, a starting point
for the actual experiment
Jacobs: Experimental Hypothesis
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•
•
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Independent Variable affects Dependant Variable
So….
Number of items affects chance of remembering
But we still need to be more exact – what items will we use and how will we
measure the chance of remembering?
• We need exact details….
Operational Hypothesis
• Puts the research hypothesis into operational termsthings we can measure and record
OK – I’ve thought about all the variables –
now let’s experiment
Laboratory Experiments
• An experiment is a controlled situation in which the
researcher manipulates one variable to discover its effect on
another variable, while all the other variables are held
constant.
• We will begin with laboratory experiments, which are
the closest to “pure science” because they give us the
most control over those variables
Labs
• Advantages of lab experiments
• In a lab it’s easy to control the
independent variable.
• All other variables can be “held
constant”
• The experiment can be replicated at
any time in the future.
• Disadvantages of lab experiments
• May lack ecological validity
• (This means what happens in the lab
may not be true to life.)
• Some situations simply cannot be
created in lab conditions.
• (Suppose we want to study why people
commit suicide )
Experimental Design
• There are three basic ways to compare run a psychology experiment.
• These are called experimental designs.
 Independent measures design
 Repeated measures design
 Matched pairs design
Sometimes we need one group
• Suppose we were studying the effect of brain surgery on a particular
psychiatric illness.
• It makes sense that we would want to study the same group before and after
the surgery, so we could see if they had improved.
• So this would have to be a repeated measures design – test the participants
before AND after.
But in many cases a repeated measures design
would be spoilt by “order effects”
• Some things are just not the same the second time around:
• The situation may only happen once in a person’s life – like learning to
read
• People may get better at the task with practice
• They may get worse due to boredom and fatigue
• They could work out the aims of the experiment and respond
accordingly – demand characteristics.
• So we would need two groups
This would be an independent measures design:
• Experimental Group
• Control Group:
• This is a group that is
• This is a group that is not
exposed to the independent
variable.
exposed to the independent
variable.
Sometimes neither method works:
• Suppose we wanted to test a new method of teaching maths.
• We would teach one group of kids with the old method and we would teach
one group with the new method.
• We couldn’t use both methods with the same group – why not ?
• But what if one group was just better than the other ?
• So here we would use a Matched Pairs Design – we use two groups, but we
make sure that the people in each group balance each other up.
Matched Pairs Design
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•
•
•
Does anyone remember “picking teams” when you played games ?
Matched pairs is a bit like that.
The group are divided up as equally as possible.
The only problem is with psychology experiments it might much more be
difficult to work out who is good at what.
Whole class activity:
• Going back to that alcohol study
• The hypothesis might be that drinking alcohol made people louder, less
inhibited, more easily amused.
• Alcohol is the IV
• Level of conversation is the DV
• But which design would we use?
• How many groups would we need?
One group or two ?
Could we use a repeated measures design ?
• We could use one group of people.
• On Friday night we give them
• But they could be more relaxed on
• On Saturday we give them non-
• They could be hung over from the
• Then we compare the two
• They may not even turn up !
• All these things distort the results.
alcohol and record their behaviour.
alcoholic drinks and record their
behaviour.
recordings.
Saturday because they haven’t been
to work.
Friday experiment,
One group or two ?
Could we use an independent measures design
?
• We could use two groups of people
• We could give one group alcoholic
drinks.
• We could give the other group nonalcoholic drinks.
• Then we could compare the
behaviour of members of each
group
• But one group may have more
people who are naturally outgoing.
• One group may have an alcoholic.
• Maybe someone just got the sack or
had some bad news about their
health.
• All these factors could change the
results
One group or two ?
What about matched pairs ?
• Our third option is to balance up
the groups by picking people who
are similar.
• So each team gets a loud person.
• Each gets a quiet one.
• Each gets a heavy drinker
• But how difficult is that going to be
when we are dealing with complex
psychological issues?
Order effects
• No matter what design you use there can still be problems with
order effects.
• Suppose you wanted to see whether different music made people
stay on a slot machine longer – by the time they move on to the
second machine they could already be bored and lose interest .
• This is a simple example of an order effect.
Counterbalancing
• These problems can be dealt with by asking your subjects to carry out the
conditions in a different order, and so balance out the order effects. This is
called counterbalancing.
• Half of the group could do Condition A, followed by condition B
• The other half could do Condition B followed by Condition A
• Just remember ABBA
ABBA
Next Week Experiments cont